This invention relates to buildings, building components, building subassemblies, and building assemblies, and to methods of constructing buildings. This invention relates specifically to components, subassemblies, and assemblies, as parts of the building, and to the issue of worker safety during the construction of buildings.
From time to time, injuries occur during construction of buildings, including to workers who fall from elevated heights. The focus of this invention is to enable a building contractor to reduce, desirably to eliminate, the number of incidents of worker injuries resulting from workers falling from elevated heights while working on construction of a building.
Governmental safety organizations, for example the Occupational Safety and Health Administration (OSHA) in the US, have promulgated required safety standards, and safety practices to generally provide safety systems which capture and support workers who are working at substantial heights above supporting surfaces, to protect such workers, namely to stop a fall, and to support such workers if/when such workers do fall. But it is up to the industry to create fall protection systems which meet the required standards.
Pre-engineered metal building systems are the predominant method of non-residential low rise construction for buildings. Existing fall protection standards have substantial impact on the contractors involved in such pre-engineered metal building systems.
One way a worker can be protected, according to the standards, is for the worker to wear a safety harness which is tied, by a strap, to the building structure at elevation such that the harness/strap combination stops any fall which the worker experiences before the worker encounters an underlying surface such as a floor or the ground. Use of such safety harness is known as “tying off”. But tying the harness to the building limits the worker's mobility, as well as the worker's range of movement. Thus, tie-off harnesses are not viewed favorably in the industry because of worker inefficiency.
Another way workers can be protected is for the building contractor to erect safety nets in order to provide leading edge protection against falls. Cost and maintenance of such safety nets, as well as the equipment and expense required for erecting and dismantling the net and associated equipment, and moving and storing the net and equipment, can be a substantial increment in the per square foot cost of especially the roof insulation system being installed.
With the anticipation of expanded enforcement efforts by government safety officials, building erectors have increased incentive to find ways to meet the existing fall protection requirements.
Another acceptable fall protection system is a passive system wherein a fabric, such as a solid sheet, a woven sheet, or a net-like material, is suspended at or below the work area, optionally supported by a grid of crossing support bands, far enough above any underlying supporting surface to catch and support a worker who falls, thereby to act as a passive fall-protection system.
OSHA has defined a drop test procedure whereby a such passive fall protection system can be tested. According to the test procedure, a 400 pound weight is dropped onto the fall protection system under stated conditions to determine whether a given system meets the required safety standards. For purposes of complying with government regulations, any system used as a fall protection system need only meet the OSHA-mandated standards related to dropping such 400 pound weight. Of course, the real humanitarian objective is to prevent worker injuries if/when a worker falls from an elevated work location. Thus, any fall protection system which is effective to catch and safely hold a falling worker has operational value, even if such system does not meet OSHA standards.
According to one aspect of the prior art, currently in use in the metal building industry, and intended to meet government fall protection standards, a purported fall protection system uses crossing longitudinal and lateral metal bands extending under the eave, under the ridge, and under the intermediate purlins, and a fabric is installed above the bands and under the purlins, extending across the entirety of a respective bay of the building being constructed, thereby providing a suspended fabric intended to catch and support a falling worker in that bay. Insulation is ultimately installed on the top surface of the fabric whereby the fabric ultimately functions as the vapor barrier portion of the building ceiling insulation system in the finished building.
Testing has shown that currently-available such systems meet the government-mandated drop test standard at certain locations in the bay of a metal building under construction, while failing such drop test at other locations. Typically, such systems fail the drop test adjacent an edge of the bay, where any worker accidental fall is most likely to occur.
In conventional fall protection systems known to the applicants, the system specifications require that the first lateral band, closest to a rafter, be spaced 6 inches from the respective rafter. Testing has shown that, when the mandated drop test is performed as close as possible to the rafter, the falling bag moves that first lateral band toward the rafter, allowing the edge of the rafter to act like a knife, cutting the fabric at the edge of the rafter. The overall result is failure of the fabric at the edge of the rafter.
Thus, the user of such conventional fall protection system cannot be assured that a falling worker will be caught and supported at whatever location he/she falls from, namely any work station at an elevated work location. Such failure can result in worker injury, along with the numerous detrimental results of such injury, as well as resulting government citations associated with the resulting injury, and associated monetary fines and/or assessments, civil lawsuits, and the like.
Accordingly, there is a need for a novel passive fall protection system for use during construction of metal buildings which effectively catches and supports a falling worker working at an elevated height anywhere in the corresponding bay being worked on, and which system meets all governmental safety standards.
There is further a need for a fall protection system which protects the suspension fabric from being cut by the edge of the rafter.
There is also a need to provide a portion of a building insulation system which functions to provide effective fall protection during construction of the building, while meeting the existing governmental fall protection requirements.
These and other needs are alleviated, or at least attenuated, or partially or completely satisfied, by novel products, systems, and/or methods of the invention.